Internship at Kwazulu-Natal Herbarium

Recently, internships were made part of the University of KwaZulu-Natal’s BSc Honours programme. Four interns were offered to the Durban Botanic Gardens (DBG) for six weeks. (Un)fortunately, the DBG could not host the fifth intern—this created an opportunity for the KwaZulu-Natal Herbarium to become involved.

Charleen Rupnarain spent 18 June–3 August at the KwaZulu-Natal Herbarium, encoding specimens of the tribes Orchideae and Diseae in the family Orchidaceae. During this period, she encoded 698 specimens. In her article below she shares her experience and illustrates the knowledge she gained from the assignment.

—Yashica Singh

My Kingdom for an Orchid

There are many myths and legends surrounding orchids; for example, the spotted leaves of Dactylorhiza were believed to be marks of blood that fell from the Cross (Griffiths 1995). In the Middle Ages in Europe, people believed that orchids grew in spots where cattle, sheep, and horses had mated.

As the legend goes, Orchid was the son of a nymph and a satyr, creatures with insatiable passion. At a festival of Bacchus, the drunk Orchid attacked a priestess and the enraged crowd leapt upon him and tore him limb from limb. His father begged the Gods to be merciful and they took pity on him. They changed Orchid into a flower with his father’s lascivious nature. From this, people believed that eating the roots of an orchid acted as an aphrodisiac (Eng Soon 1980).

The word “orchid” is derived from “orchis” (Greek for testis). Theophrastus (370–285 BC) made this association when he noticed the similarity between the bulbs of Mediterranean orchids and the mammalian testes. Carl Linnaeus kept the word in his Species Plantarum, which was the origin of binomial classification (Eng Soon 1980).

Wild orchids will thrive in almost any undisturbed place that can support plant life. Despite this, they are actually quite rare plants. This is because of the high degree to which they are affected by environmental change. Another reason limiting their abundance is their difficulty in reproducing. Orchids produce thousands of seeds per capsule, but these seeds do not contain any storage or nutrient tissue. They will only germinate when an association with a specific fungus is made (Eng Soon 1980). Habitat destruction—forestry, pollution, farming, plantations, industry, and general urbanisation—has also resulted in restricted or decreased numbers of orchids. Many orchids, such as Bonatea saundersiae, Cynorchis compacta, and Disa zuluensis, are now afforded protection by the CITES II Convention and efforts are made to increase their declining numbers (Scott-Shaw 1999), including micropropagation in labs to build up seedling reserves.

The Orchidaceae comprises 22,000–25,000 species and is the largest angiosperm family. In South Africa, there are 466 species of orchids in 52 genera, of which 302 species in eight genera are endemic. Linder and Kurzweil (1999) have recorded that the Western Cape has the largest number of species and the greatest diversity of orchids. The only orchid species that has been introduced to South Africa is Gastrodia sesamoides (Linder and Kurzeil 1999).

Orchids are divided into two groups based on the number of anthers. The subfamily Orchidoideae belongs to the monandrous orchids—they have one functional stamen. The subfamily is then divided into tribes based on a number of characters such as vegetative features, floral features, and habitat (Burns-Balagh & Funk 1986). Most of the South African orchids belong to this subfamily.

Members of the Orchideae tribe have an erect or suberect anther; the lip is frequently spurred, whereas the median sepal is not; the petals are not stalked and often are not lobed, but they are never fimbriate. On the other hand, members of the Diseae tribe have an anther that is horizontally reflexed, or if the anther is erect, the median sepal is spurred and the petals are fimbriate with a long claw (Linder & Kurzweil 1999).

Like other families, the genera making up the Orchidaceae have had their names changed many times after revisions. New genera have been described; some have been excluded and their species put into pre-existing genera. This process is continuous as new information comes into being and systematists employ new scientific methods, for example, comparison of nucleotides. For instance, Monadenia and Herschelia are now included in the genus Disa and what is now the genus Corycium was once viewed as part of the genus Pterygodium.

During my internship at the KwaZulu-Natal Herbarium, I encoded the specimens of the tribes Orchideae and Diseae. The records from the data captured showed that Kwazulu-Natal had the largest number of species (52 Orchideae species and 74 Diseae species) followed by the Eastern Cape (29 Orchideae species and 61 Diseae species). The tribes Orchideae and Diseae are found mainly in soil in grasslands, on slopes, in marshy areas, forests, and on cliffs. They have rarely been recorded in dry conditions. I found the most ardent orchid collectors to be F.R.R. Schlechter, H.J. Thode, S.P. Bester, J.M. Wylie, R. Williams, J. Medley-Wood, and A.G.H. Rudatis. The collector that made the largest contribution to the herbarium’s collection of Orchideae and Diseae is Medley-Wood, who collected over 130 specimens.

South African orchids are not very popular for cultivation because their flowers tend to be small and unappealing to horticulturalists. The large-flowered species from Tropical America and Asia are generally preferred (Linder & Kurzweil 1999). Despite this, South African orchids have a lot to offer to a garden. The flowers of Stenoglottis may be small but they bloom during summer and autumn when few orchids can be found in flower (Stewart 1989). Having a plant such as this, along with other spring-flowering orchids, would result in a garden blooming all year round. The best-known orchid in the commercial world is perhaps Vanilla, a very primitive orchid dating back 120 million years ago (Leroy-Terquem & Parisot 1993). The Vanilla fruit are the source of the well-known flavouring. In South Africa, orchids are used as food, aphrodisiacs, fertility charms, poison, medicine, and as talismans.

“Orchid fever” hit Europe in the 19th century, resulting in orchids being sold at ridiculously high prices at auction houses; one orchid was sold for 100 times the average salary of a domestic worker (Leroy- Terquem & Parisot 1993). Orchids have been the hobby of heads of royalty and have had praise heaped upon their beauty and mystery by poets and authors. Today their magic is still present—enjoying their loveliness is not restricted to the lucky few anymore, but is open to anybody who cares to indulge in them. No longer need I give up my kingdom for an orchid!

—by Charleen Rupnarain

SABONET News 6.3: 230

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BURNS-BALAGH, P. & FUNK, V.A. 1986. A phylogenetic analysis of the Orchidaceae. Smithsonian Contributions to Botany 61. Smithsonian Institution Press, Washington.

ENG SOON, T. 1980. Asian orchids. Times Books International, Singapore.

GRIFFITHS, M. 1995. In: J. Stewart & M. Griffiths (eds), Manual of orchids. Macmillan Reference Books, London.

HUNT, P.F. 1990. The orchids: the wild species. W.H. Smith Publishers Inc., New York.

LEROY-TERQUEM, G. & PARISOT, J. 1993. Orchids: care and cultivation. Cassell Publishers Ltd, London.

LINDER, H.P. & KURZWEIL, H. 1999. Orchids of southern Africa. A.A. Balkema, Rotterdam, Brookfield, Netherlands.

SCOTT-SHAW, R. 1999. Rare and threatened plants of KZN and neighbouring regions. Pietermaritzburg, KZN Nature Conservation Service.

STEWART, J. 1989. The genus Stenoglottis. The Kew Magazine 6, 1 (February 1989).